package com.gqr.lock.lock;

import java.util.Random;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 *  用tryLock来避免死锁
 */
public class TryLockDeadlock implements Runnable{

    int flag = 1;
    static Lock lock1 = new ReentrantLock();
    static Lock lock2 = new ReentrantLock();

    public static void main(String[] args) {
        TryLockDeadlock r1 = new TryLockDeadlock();
        TryLockDeadlock r2 = new TryLockDeadlock();
        r1.flag=1;
        r2.flag=0;
        new Thread(r1).start();
        new Thread(r2).start();
    }
    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            if (flag==1){
                try {
                    if(lock1.tryLock(800, TimeUnit.MILLISECONDS)){
                        try{
                            System.out.println("线程1获取到了锁1");
                            Thread.sleep(new Random().nextInt(1000));

                            if (lock2.tryLock(800, TimeUnit.MILLISECONDS)){
                                try{
                                    System.out.println("线程1获取到了锁2");
                                    System.out.println("线程1成功获取到了两把锁");
                                    break;
                                }finally {
                                    lock2.unlock();
                                }
                            }else{
                                System.out.println("线程1获取锁2失败，已重试");
                            }
                        }finally {
                            lock1.unlock();
                            Thread.sleep(new Random().nextInt(1000));
                        }

                    }else{
                        System.out.println("线程1获取锁1失败，已重试");
                    }
                }catch (InterruptedException e){
                    e.printStackTrace();
                }

            }

            if (flag==0){
                try {
                    if(lock2.tryLock(3000, TimeUnit.MILLISECONDS)){
                        try{
                            System.out.println("线程2获取到了锁2");
                            Thread.sleep(new Random().nextInt(1000));

                            if (lock1.tryLock(800, TimeUnit.MILLISECONDS)){
                                try{
                                    System.out.println("线程2获取到了锁1");
                                    System.out.println("线程2成功获取到了两把锁");
                                    break;
                                }finally {
                                    lock1.unlock();
                                }
                            }else{
                                System.out.println("线程2获取锁1失败，已重试");
                            }
                        }finally {
                            lock2.unlock();
                            Thread.sleep(new Random().nextInt(1000));
                        }

                    }else{
                        System.out.println("线程2获取锁2失败，已重试");
                    }
                }catch (InterruptedException e){
                    e.printStackTrace();
                }

            }
        }

    }
}
